• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 33 subscribers
  • Views 468 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

SN65HVDA100 / Is there any standard way of generating the "break field" with 13 low bits for the Lin bus?

Martin Grimmer
Prodigy 510 points
Other Parts Discussed in Thread: SN65HVDA100

Hi,

my customer is asking following question:

‘’I would like to use the SN65HVDA100.

The microcontroller I am using has a UART which only can generate 8,7 or 6 bit data words.

For the LIN bus the "break field" should have 13 bits. I have noticed the SN65HVDA100 outputs the same signal on the LIN bus as I generate on the UART side.

Is there any standard way of generating the "break field" with 13 low bits for the Lin bus with the SN65HVDA100?

I would think most of the UARTs on the microcontroller side cannot generate the 13 bits."

Thank you for any recommendation.

BR Martin

  • 0
    TI__Genius 16410 points
    Hello Martin,

    Let me move this to the Industrial Interface forum, where this device is support. They should be able to help you.

    Regards,
    Karl
  • 0 in reply to Karl Wallinger
    TI__Guru** 103215 points
    Hello Martin,

    I'm not familiar with the capabilities of your MCU producing the UART signal. If the MCU can produce 7 and 6 bit words is there a reason why you can't combine a 6 bit and 7 bit word (all low) to generate a 13 bit low signal for the HVDA100? As long as the signal does not return high between words that should be ok. If I know more about the MCU side I may be able to direct you to more assistance if this does not solve your problem. The HVDA100 has no means of generating a break field since the part only deals with the physical layer of the LIN system.

    Best Regards,
    Casey McCrea
  • 0 in reply to Casey McCrea
    TI__Prodigy 510 points
    Hello Casey,

    customer is using a UART from a TI DSP, which is connected to the SN65HVDA100. The UART only can generate words with 8, 7 or 6 bits. He tried to send two words with 8 bit each, but the UART generates a stop bit in between. Then it is not a proper break field and the slave cannot detect it. For the rest of the message He needs the stop bit according to the LIN specification, so he cannot disable the stop bit. Do you know if there is a standard way of generating the break field? This device is probably more often connected to a UART.

    Best Regards
    Martin Grimmer
  • 0 in reply to Martin Grimmer
    TI__Guru** 103215 points

    Hello Martin,

    I understand that the stop bit is preventing you from stringing together two words to generate the appropriate field. In order to get you more help with this problem you will need to contact a group that deals with the the data link layer rather than physical layer. If you let me know which specific DSP you are using I can direct you to the appropriate group. 

    Best Regards,

    Casey McCrea